A Sesame Street game for the Commodore 64 back in '84 I think. As soon as I was old enough to hold the controller my dad put it in my hand. He used to pirate games with dual floppy drives, I played literally hundreds of games for that thing.
The NES was awesome, but what really hooked me again and has had me in love with gaming since was the first time I saw Sonic on a Sega Genesis a friend had imported. Blast Processing!